This invention relates to hand held automatic firearms--namely firearms that automatically extract a spent cartridge from a firing chamber after a shot is fired, retract the bolt, eject the cartridge and present a fresh cartridge to the chamber for a subsequent shot whereby continued depression of the trigger is effective to fire repeated shots until the trigger is released. More particularly the invention relates to machine pistols working on the blowback principle with open bolt operation, and especially to a light weight weapon with means to retard blowback of the bolt mechanism in order to reduce the cyclic firing rate and improve controllability.
Machine (fully automatic) pistols are generally available and useful only for limited purposes such as military applications to include counter-insurgency and anti-terrorist type missions and police special weapons team operations. While these light weight automatic weapons are highly respected for their capabilities, they do have certain limitations and require considerable strength and skill on the part of the operator.
A recent improvement in the design of hand held automatic firearms to improve the ease of handling and accuracy is shown in my U.S. Pat. No. 4,321,765, the disclosure of which is incorporated by reference herein and made a part hereof. The holding apparatus shown therein is incorporated in the design of the machine pistol of the present invention.
Briefly, that holding apparatus includes separate right hand and left hand stocks, the right hand stock being a generally conventional pistol grip wherein the trigger finger is placed through the trigger guard in position to squeeze the trigger. The weapon is held in a generally horizontal position with the right hand stock extending laterally to the right so that the palm of the operator's right hand is horizontal. The left hand stock extends from the opposite side of the weapon and includes a left hand grip so formed that the palm of the operator's left hand is generally vertical. Accordingly, the operator's comparable wrist axes are perpendicular to one another, thus providing an improved capability for controlling the weapon.
One problem with machine pistols in the past has been the inherent high cyclic firing rate that results when an attempt is made to reduce weight and improve ease of handling.
In heavier blow-kick-type, automatic firearms such as sub-machines guns that may be fired from the waist or while supported by a sling, the mass of the bolt assembly is sufficient to provide the inertia needed to maintain a desired firing rate and thus achieve satisfactory controllability and accuracy. In the lighter type of automatic weapon, however, the inertia of the bolt assembly is relatively small. Accordingly higher cyclic firing rates result and in turn a reduced controllability.
The result is that the weapon is less accurate, the ammunition is used less effectively in that too many rounds are fired for each depression of the trigger and the operator must use excess time and effort in unloading and reloading ammunition clips.
The machine pistol of the present invention however provides a novel retarded blowback arrangement (and thus a reduced cyclic firing rate) in a design incorporating light-weight components (including the bolt assembly) and affords other features and advantages heretofore not obtainable.